<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <div id="app">
      <h1>{{html}}</h1>
      <button @click="fn">逆转世界</button>
    </div>
  </body>
  <script src="./vue.js"></script>
  <script>
    const app = new Vue({
      el: '#app',
      data: {
        html: 'Hello,world'
      },
      methods: {
        fn() {
          //   if (this.html === 'Hello,world') {
          //     this.html = 'dlroW,olleH'
          //   } else {
          //     this.html = 'Hello,world'
          //   }
          this.html = this.html.split('').reverse().join('')
        }
      }
    })
  </script>
</html>
